This invention relates to various resin compositions comprising a resin component containing compound (A) wherein or a part of oxirane ring in an epoxy compound is replaced with thiirane ring; or the compound (A) and compound (B) which contains oxirane ring and no thiirane ring in the molecule.
More specifically, this invention relates to:
(i) an adhesive composition comprising the resin component as described above;
(ii) a resin composition for a sealant exhibiting excellent adhesion and tensile strength comprising the resin component as described above and another particular resin;
(iii) a resin composition for a coating composition and a coating agent comprising the resin component as described above exhibiting excellent curability, adhesion to adherend, and reduced odor without detracting from pot life;
(iv) a resin composition for electric applications comprising the resin component as described above which quickly develops electric insulation, which exhibits flame retardancy, excellent curability and strong adhesion to metal substrate, and which can be used for potting of print circuit boards and as a resin for impregnation in prepregs;
(v) a resin composition comprising the resin component as described above exhibiting excellent fast curing, and in particular, fast curing at low temperatures as well as high storage stability at high temperatures;
(vi) a resin composition suitable for use as an adhesive and the like comprising the resin component as described above and a particular phosphite ester, which exhibits excellent adhesion, curability at low temperatures, reduced odor, and good storage stability;
(vii) a fast curing, one part resin composition suitable for use as a coating composition, adhesive and the like comprising the resin component as described above and a particular ketimine, which exhibits excellent curability at low temperatures and storage stability; and
(viii) a resin composition further comprising a reactive diluent capable of reducing viscosity of the composition, and which exhibits no clouding of the composition by the crystallization of the resin component as described above.
Epoxy resin-based adhesives are widely used in various industrial fields since they exhibit satisfactory adhesion to a variety of materials such as metals, plastics, woods, glass, concrete, and ceramics, and at the same time, excellent heat resistance, chemical resistance, electric insulation, and the like. Accordingly, they are used as an adhesive for supporting the structure of automobiles and airplanes, and as an adhesive for civil engineering and construction purposes.
Recently, epoxy resin-based adhesives are also finding their use in the field of electrical and electronic engineering since they are excellent in properties such as heat resistance band electric insulation and the gas generated and shrinkage in the course of curing are reduced.
For example, Epoxy resin-based adhesives are used as a potting agent for physical and chemical protection and fixation of print circuit boards and as a resin for impregnation in prepregs. As a consequence of such widening in the range of their application, there is a demand for epoxy resin-based adhesives to have further improved electric insulation, flame retardancy, and adhesion. There is also a demand for further reduction in curing time without detracting from their electric insulation for the purpose of shortening the production period.
In spite of such situation, most of the conventional epoxy resin compositions have been two part compositions comprising the main part and the curing agent. Such two part compositions suffer from short pot life since the curing reaction starts immediately after the mixing of the components, and as a consequence, the composition suffered from poor workability.
A typical method for extending the pot life is use of a latent curing agent, for example, a block isocyanate-modified epoxy resin. A latent curing agent, however, is an agent primarily developed for curing by heat application, and the performance upon drying at room temperature has been far from being acceptable for practical use. Another method is use of a resin with low reactivity, for example, an aliphatic epoxy resin for the main part. This method, however, suffers from reduced working efficiency due to inferior drying properties and markedly delayed formation of the surface film despite the extended pot life.
The composition can be imparted with fast curing properties when a thiol compound is used as a curing agent. Thiol compounds, however, suffer from bad odor and use of such compounds invites worsening in the work environment.
Adhesive strength of the epoxy resin-based adhesives has been conceived to be developed mainly by the hydroxyl group which is generated as a result of the curing reaction. This hydroxyl group, however, has low reactivity (acidity), and the adhesive strength is believed to be developed by physical affinity. Accordingly, introduction in the molecule of a highly reactive functional group which can generate a substituent having a chemical reactivity higher than that of the hydroxyl group upon curing may result in the production of an adhesive which exhibits stronger adhesive strength and faster curing compared to the conventional epoxy resin-based adhesives or a coating composition, a coating agent, or a potting agent which exhibits stronger adhesion or bonding to the substrate as well as faster curing compared to the conventional epoxy resin composition.
In the case of the two part, room temperature-curable epoxy resin-based adhesive used in outdoors, balance between the pot life and the curing speed is important. The adhesives wherein an aliphaticpolyamine is used for the curing agent had the merit of high curing speed while they suffered from short pot life. On the other hand, the adhesives wherein an alicyclic polyamine compound is used for the curing agent had the merit of extended pot life and reduced heat generation while they suffered from low curing speed and difficulty in curing at low temperatures.
Thiirane-containing resin wherein oxirane ring of the epoxy resin is replaced with thiirane ring exhibits higher reactivity and faster curing speed at low temperatures since thiirane ring has a reactivity higher than the oxirane ring because of the higher distortion of the thiirane ring compared to the oxirane ring. Such thiirane-containing resin also exhibits low temperature curability, good adhesion and reduced odor since the thiol group generated by the ring opening is a substituent having a high chemical reactivity. Thiirane-containing resin, however, suffered from poor storage stability, and in particular, from poor storage stability at a high temperature, for example, at 60xc2x0 C. because of the high chemical reactivity of the thiol group.
JP-A 10-130513 discloses a method for preventing alteration in quality of mercapto group (xe2x80x94SH)-containing polymer wherein a primary antioxidant such as an alkylphenol-based oxidant or an amine-based oxidant and a secondary antioxidant such as a sulfur-based antioxidant or a phosphorus-based antioxidant are simultaneously incorporated in the polymer to suppress the oxygen concentration of the gas phase part below the predetermined volume. However, incorporation in the thiirane-containing resin of an alkylphenol compound which is a versatile antioxidant proved to have no influence in improving the storage stability.
JP-A 5-132541, JP-A 5-230182 and the like disclose one-part epoxy resin compositions wherein the epoxy resin has a ketimine compound blended therewith as a latent curing agent. Ketimine compound, however, suffers from a drawback that amine which generates in the course of the hydrolysis (equilibrium) reaction in the presence of water contributes for the curing reaction and as a consequence, the curing proceeds at an extremely slow speed, and in particular, the resin does not cure at a low temperature, for example, at a temperature not more than 5xc2x0 C.
On the other hand, a thiirane-containing resin wherein oxirane ring of an epoxy resin is replaced with thiirane ring exhibits high reactivity, and fast curing properties at low temperatures, since the ring of thiirane ring is more distorted than the oxirane ring. The thiirane-containing resin also exhibits excellent low temperature curability, good adhesion and reduced odor since the thiol group generated by the ring opening of the thiirane group is a substituent of high chemical reactivity. The high chemical reactivity of thiol group, however, sometimes results in reduced storage stability of the thiirane-containing resin as well as higher viscosity and susceptibility to crystallization of the thiirane-containing resin.
In addition to the high viscosity, the thiirane-containing resin also suffers from problems, namely, reduced workability by the viscosity increase in the prolonged storage, poor appearance by the clouding of the resin composition caused by crystallization, or even from poor workability by solidification.
When the thiirane-containing resin was blended with a reactive diluent such as a glycidyl ether compound to obviate the problems as described above, the thiirane-containing resin experienced rapid crystallization, and the problems of poor appearance and reduced workability could not be obviated.
In view of such situation, the objects of the present invention are:
to provide an adhesive composition which exhibits adhesive strength and fast curing properties higher than the conventional epoxy resin-based adhesives, and which is adapted for use as an adhesive for rubbers, metals, and plastics;
to provide an adhesive composition which exhibits well-balanced pot life and low temperature curability as well as good adhesion;
to provide an adhesive composition which exhibits adhesive strength, fast curing properties, and flexibility higher than the conventional epoxy resin-based adhesives as well as reduced odor, and which is adapted for use as an adhesive for civil engineering and construction purposes;
to provide a resin composition containing the resin of particular type which is adapted for use as a sealant and which exhibits improved adhesion and tensile strength;
to provide a resin composition adapted for used as a coating composition and a coating agent which exhibits excellent curability simultaneously with extended pot life, and higher adhesive strength to the substrate and less odor compared to the conventional epoxy resin-based adhesives;
to provide a resin composition for electric applications which is capable of developing electric insulation faster than the conventional resin compositions for electric applications as well as flame retardancy, which exhibits excellent curability and good adhesion to metals, and which is adapted for use as a potting resin for a print circuit board, a resin to be impregnated in a prepreg, and the like;
to provide a resin composition which exhibits satisfactory storage stability at high temperatures without detracting from the high curing speed;
to provide a resin composition which exhibits excellent adhesion and low temperature curability as well as reduced odor and satisfactory storage stability;
to provide a fast curing, one part resin composition which exhibits excellent low temperature curability and storage stability, and which is adapted for use as an adhesive adapted for use as a coating composition, adhesive, and the like;
to provide a resin composition wherein crystallization of the resin is suppressed to prevent clouding that adversely affect the outer appearance of the resin composition, and which has reduced viscosity.
In order to obviate the problems as described above, the present invention provides an adhesive composition containing compound (A) wherein all or a part of oxirane ring in an epoxy compound is replaced with thiirane ring (group) represented by the following formula (1): 
or the compound (A) and compound (B) which contains oxirane ring and no thiirane ring in the molecule; wherein the ratio of oxirane ring/thiirane ring (group) is from 90/10 to 10/90.
The present invention also provides an adhesive composition containing the compound (A) or the compounds (A) and (B), wherein said composition contains oxirane ring and thiirane ring at a ratio of oxirane ring/thiirane ring of 90/10 to 10/90; and wherein said composition further contains at least one curing agent selected from the group consisting of compounds containing hydroxyl group, mercapto group, amino group, carboxyl group or isocyanate group and compounds having acid anhydride structure.
The present invention also provides an adhesive composition wherein, when said curing agent is a compound containing amino group, at least one alicyclic polyamine compound is included in the composition.
The present invention also provides an adhesive composition wherein said composition further comprises a liquid curing agent having a viscosity at 25xc2x0 C. of up to 100,000 mPaxc2x7s.
Viscosity at 25xc2x0 C. of said compound (A) or said compounds (A) and (B) is preferably up to 100,000 mPaxc2x7s.
When content of thiirane (molar fraction (%) of thiirane ring in the total of oxirane ring and thiirane ring in the compound containing oxirane ring and/or thiirane ring) is x, and equivalent ratio of the curing agent to the total of oxirane ring and thiirane ring is y, x and y may preferably meet the following relations (1) and (2):
when
10%xe2x89xa6x less than 50%,
y=(1xe2x88x92x/100)xc2x10.2xe2x80x83xe2x80x83(1),
and when
50%xe2x89xa6xxe2x89xa690%,
0.1xe2x89xa6yxe2x89xa60.7xe2x80x83xe2x80x83(2).
The present invention also provides a resin composition for a sealant containing at least one member selected from the group consisting of polysulfide resin, urethane resin, silicone resin, modified silicone resin and butyl rubber; and said adhesive composition.
The present invention also provides a resin composition for a sealant which further comprises 10 to 200 parts by weight of an inorganic filler and 10 to 200 parts by weight of a plasticizer per 100 parts by weight of said compound (A) or total of said compounds (A) and (B).
The present invention also provides a resin composition for a coating composition and a coating agent containing the compound (A) or the compounds (A) and (B), wherein said composition contains oxirane ring and thiirane ring at a ratio of oxirane ring/thiirane ring of 95/5 to 1/99, and wherein said composition further contains at least one curing agent selected from the group consisting of compounds containing hydroxyl group, mercapto group, amino group, or carboxyl group.
In said resin composition for a coating composition and a coating agent, when content of thiirane is x, and equivalent ratio of the curing agent to the total of oxirane ring and thiirane ring is y, x and y may preferably meet the following relations (1) and (2):
when
5%xe2x89xa6x less than 50%,
y=(100xe2x88x92x)/100xc2x10.2xe2x80x83xe2x80x83(1),
and when
50%xe2x89xa6xxe2x89xa699%,
0.1xe2x89xa6yxe2x89xa60.7xe2x80x83xe2x80x83(2).
The resin composition may preferably further comprise 3 to 50 parts by weight of a filler for modification per 100 parts by weight of said compound (A) or total of said compounds (A) and (B).
The present invention also provides a resin composition for electric applications containing the compound (A), or the compound (A) and the compound (B); wherein said composition contains oxirane ring and thiirane ring at a ratio of oxirane ring/thiirane ring of 95/5 to 1/99; and wherein said composition further contains at least one curing agent selected from the group consisting of compounds containing hydroxyl group, mercapto group, amino group, or carboxyl group.
In the resin composition for electric application, when content of thiirane is x, and equivalent ratio of the curing agent to the total of oxirane ring and thiirane ring is y, x and y may preferably meet the following relations:
when
5%xe2x89xa6x less than 50%,
y=(100xe2x88x92x)/100xc2x10.2xe2x80x83xe2x80x83(1),
and when
50%xe2x89xa6xxe2x89xa699%,
0.1xe2x89xa6yxe2x89xa60.7xe2x80x83xe2x80x83(2)
in view of the adhesion performance.
The resin composition may further comprise 2 to 30 parts by weight of a flame retardant per 100 parts by weight of said compound (A) or total of said compounds (A) and (B).
The present invention also provides a resin composition containing the compound (A) wherein said composition contains oxirane ring and thiirane ring at a ratio of oxirane ring/thiirane ring of 95/5 to 1/99, and has a moisture content of: 1000xe2x88x9210x (ppm) or less when x represents content (%) of thiirane.
The resin composition may preferably further comprise 1 to 100 parts by weight of a dehydrating agent per 100 parts by weight of the compound having oxirane ring and/or thiirane ring.
The resin composition may preferably further comprise at least one curing agent selected from the group consisting of compounds containing hydroxyl group, mercapto group, amino group, carboxyl group or isocyanate group and compounds having acid anhydride structure.
The present invention also provides a resin composition containing a resin component comprising the compound (A) or the compounds (A) and (B), and a phosphite ester compound; wherein said resin component contains oxirane ring and thiirane ring at a ratio of oxirane ring/thiirane ring of 95/5 to 1/99.
The resin composition may preferably contain said phosphite ester compound at a content of 0.1 to 30 parts by weight per 100 parts by weight of said resin component.
Said phosphite ester compound may preferably contain at least one member selected from the group consisting of phosphite ester compounds represented by the following structural formula (2) or (3): 
wherein R1 to R5 represent a hydrocarbon group containing up to 30 carbon atoms.
Said ester phosphite compound may preferably contain at least one member selected from the group consisting of phosphite ester compounds wherein at least one of R1 to R3 in the structural formula (2) is an aromatic ring and phosphite ester compounds wherein at least one of R4 and R5 in the structural formula (3) is an aromatic ring.
In said structural formula (2), the phosphite ester compounds wherein at least one of R1 to R3 is an aromatic ring is preferably a diarylmonoalkyl phosphite.
The resin composition may preferably further comprise at least one curing agent selected from the group consisting of compounds containing hydroxyl group, mercapto group, amino group, carboxyl group or isocyanate group and compounds having acid anhydride structure.
The present invention also provides a fast curing, one part resin composition containing a resin component containing oxirane ring and thiirane ring at a ratio of oxirane ring/thiirane ring of 95/5 to 1/99; and a ketimine compound.
Said ketimine compound is preferably the one synthesized from a compound containing primary amino group bonded to secondary or tertiary carbon and a ketone.
Said ketimine compound is preferably the one synthesized from a compound containing primary amino group bonded to primary carbon and a ketone having a substituent at xcex1 position.
The resin composition may preferably further comprise at least one member selected from the group consisting of phosphite ester compounds having the structural formula (2) or (3) at a content of 0.1 to 30 parts by weight per 100 parts by weight of said resin component.
The present invention also provides a resin composition containing a resin component comprising the compound (A) or the compounds (A) and (B), and a liquid glycidylamine compound; wherein weight ratio of said resin component to said liquid glycidylamine compound is 95/5 to 60/40.
Said liquid glycidylamine compound is preferably a liquid diglycidylamine compound.
The resin composition may preferably further comprise a phosphite ester compound at a content of 0.1 to 30 parts by weight per 100 parts by weight of said compound having at least one of oxirane ring and thiirane ring, and the phosphite compound is preferably the phosphite compounds having phenyl group and an alkyl group represented by the structural formula (2) or phosphite compounds having Spiro skeleton represented by the structural formula (3).
The resin composition may preferably further comprise at least one curing agent selected from the group consisting of compounds containing hydroxyl group, mercapto group, amino group, carboxyl group, isocyanate group, or imine group and compounds having acid anhydride structure.
Said compound (A) is preferably a compound wherein all or a part of oxirane ring in an epoxy compound of bisphenol F glycidyl ether type is replaced with thiirane ring represented by said structural formula (1).
Said compound (B) is preferably an epoxy resin which is a glycidyl ether of bisphenol F.